[PATCH] PCI Hotplug: rpaphp: Change slot pci reference

The slot structure in the rpaphp module currently references the PCI
contents of the slot using the PCI device of the parent bridge.  This
is unnecessary, since the module is actually interested in the
subordinate bus of the bridge.  The dependency on a PCI bridge device
also prohibits the module from registering hotplug slots that have a
root bridge as a parent, since root bridges on PPC64 don't have PCI
devices.

This patch changes struct slot to reference the PCI subsystem using a
pci_bus rather than a pci_dev.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>